It is simple, imagine you were the FD of a SME who uses a certain tech, but it is incidental to the business. You have two proposals put to you, and one of them is various strung together FOSS solutions and the other MICROSOFT. You take a personal risk by approving the project. Do you have time/ability to dig down into the risks/payoff for the other solution. £20k on a db from a brand you trust, as part of a £250k project. Would you quibble over it? That is why people pay the money.